Pneumatic nail driver



July 20, 1948. r w. E. KENDALL 2,445,674

' ruzumncmn DRIVER Filed March 3, 1945 2 Shee'tS-Sheet 1 Patented July20, 1948 PNEUMATIC NAIL DRIVER Willard E. Kendall, Fltehburg, Mass.

. Application March 3, 1945, Serial No. 580,778

6Claims. 1

This invention relates to a nailing machine,

which is constructed with means for nailing by the air operation of thedriving hammer or ram, and with means for feeding nails spaced apart ona fragile or easily breakable paper or plastic strip to the drivinghammer or ram.

One of the objects of the invention is to provide an automatic feedinghand carried nailing machine, which will continue to operate under airor other similar pressure, to successively drive nails into worlr, bythe manual pressure of a release valve.

Another object of the invention is the provision of a machine of thistype with a nail strip track, and air channels so located that the nailsare advanced along this track to driving position, by the impulse actionof released air.

With the above and other objects in view the invention consists incertain new and useful constructions, combinations and arrangements ofparts, clearly described in the following specification, and fullyillustrated in the accompanying drawings, in which:

Fig. 1 is a side elevation of the chine.

Fig. 2 is a top plan view thereof.

Fig. 3 is a detail vertical sectional view, taken on line 3-3 of Fig. 1,looking in the direction of the arrows.

Fig. 4 is a central, vertical and longitudinal sectional view, taken online 4-4 of Fig. 2, looking in the direction of the arrows.

Fig. 5 is a detail perspective view of a nail trap and guide.

Referring to the accompanying drawings which are illustrative of thepractical design by which the invention is carried out, 5 designates aframe casting, which is constructed to provide a vertical cylinder 6,having a liner 1, for the piston 8. This piston is equipped with adetachable head disc 9, which is secured in place by means of the screwN, which is retained by lock washer II. This disc 9 holds the packingwasher ll against the head of the piston, to prevent leakage along thesides of the piston.

The piston carries a ram or hammer rod l2,

improved mawhich is coupled thereto by screw threads, and

the lower end of this rod slides in the ram or hammer guide passage l3,formed in axial alignment with the cylinder 8. A coiled compressionspring I! surrounds the hammer rod It with its upper end engaging aiocknut I! which serves to lock the piston on the "rod II. The oppositeend of the spring I seats on the bottom wall of a spring well I! formedin the frame immediately beneath the cylinder 5. The upper end of thecylinder is closed by a cap it, secured in place by screws 18, andsealed by the gasket 20. This cap also serves to hold the cylinder linerin place.

Nails are fed to the ram or hammer rod guide passage l3 along thehorizontal track 2|, which is shown to be disposed at right angles tothe vertical axis of the ram or hammer rod. The nails 22 are arranged ona carrier strip 23 of easily breakable plastic or paper or othermaterial, and a plate 24 is detachably. secured to the bottom of theframe to close the longitudinal opening below the track and its strip ofnails.

The entire track may be removed by the withdrawal of the dowel pins 25and other tracks substituted for the accommodation of nails of differentsizes.

The frame includes the upper horizontal bar 26, which has an air feedpassage 26a which communicates with the air pressure chamber 21 abovethe piston, through the inlet port 28 in the wall of the liner and thewall of the cylinder, which port is never closed by the return movementof the piston, under the reaction'of its spring. Formed in the bar 26 isa recess 26 which intersects the air feed passage 26a and opens throughthe top side of the bar 26. The open end of the recess 26' is somewhatenlarged and internally screw-threaded for a purpose to be more fullyset forth. Flow of air through the air feed passage 26a is controlled bymeans of a manually operated-button valve unit designated generally 29,which is seated in the recess 26' as shown in Figure 4.

This button valve unit 29 comprises a bushing or thimble 32 in which avalve piston 2! slides longitudinally. Seated on the bottom wall of thethimble 32 is a compression coiled spring 30 the opposite end of whichbears against the innermost end of the valve piston 29 to normally urgeit outwardly through the open end of the thimble. Formed in the sidewall of the valve piston 29 intermediate its ends is a longitudinallyextending groove 29" into which a pin 29'" extending radially throughthe side wall of the thimble projects was to retain the valve pistontherein for limited movement. Intermediate the ends of the thimble arealigning openings 32a which align with the air feed passage 25a.Extending transversely of the valve piston on'an axis' perpendicular tothe pin 29" is a passage 29a which when the valve piston is pressedinwardlyagdi'nst the spring ill aligns with the openings fua toestablish communication between the air feed passage 26a and the inletport 28. As previously stated the button valve unit 29 is received inthe recess 26', a sealing gasket 34 is then inserted to rest upon theend of the thimble 32 and an externally screw-threaded ring nut 38 isentered into the threaded end of the recess to hold the valve unit 29 inplace and effectively seal the whole against air. leakage.

From the passage 26a, forwardly of the valve unit 29, a vertical reliefair passage 35 is formed, which leads through the frame. to the track2|, and which discharges air directly against the strip nails throughthe forwardly and downwardly deflected outlet 35a thereof, near thedischarge forward end -of this track 2i. Another air relief opening orpassage 38 leads from the bottom of the cylinder to this outlet 35a.Another relief air passage 31 leads from the wall of the liner and thecylinder, midway of the same. to the air relief passage 35.

When air is released by the manual operation of the button valve, theair will flow downwardly through the passage 35 and out through theoutlet 35a, thus tending to hold the carrier strip forwardly and theforemost nail in the path of the hammer. As the piston descends air willbe forced out of the cylinder into the passage 35, to further augmentthe holding effect. As the hammer descends it will first encounter thenail head of the foremost nail in the strip and after driving the nailthrough the strip will shear that portion of the strip lying in its pathfrom the remainder of the carrier strip and carry the sheared portionagainst the work as the nail is driven home. Having driven the nailhome, pressure on the button valve is released thus cutting off thesupply of air pressure to the piston through the passage 28a. The piston8 and hammer l2 then return to retracted position under the influence ofthe spring ll. The air remaining in the chamber 21 behind the piston i2is displaced by such movement of the piston and flows through the port28 into the passage 35 to be directed against the carrier strip 23 tocause it to move and advance the next successive nail into the path ofthe hammer ready for a repeat operation. It is to be understood ofcourse that the distance between the nails and the strip 23 is equal tothe diameter of the hammer so that as the strip lengths are sheared off,the

nails will be brought 'in succession into axial alignment with thehammer.

From the rear or inlet side of the main air feed passa e 26a an airpassage 38 leads to the track 2|, rearwardiy of the discharge port oroutlet 35a. The flow of air through this passage may be controlled bymeans of a manual valve 39. By operating this valve the air flow may beregulated or stopped and the air flowing through this passage 38 willserve to aid in holding and advancing the carrier strip 23.

The frame is constructed with an integral nail discharge tube or guide40, and in the bore of this tube or guide a nail restraining member 4|is secured, as by the screw pins 42. This guide or member is providedwith a series of radially yielding fingers 43, which may be madeofgrubber or spring metal, and which are adapted to' yield outwardlyunder the driving force of the ram or hammer rod, when air pressure isapplied thereto. The nail restraining member also serves as a guide todirect the nail straight into the object.

Air is supplied to the main air feed passage 28a by means of the airconduit M, which is coupled thereto, by the bushing 45.

By succesively operating the manual valve nails may be successivelydriven from the nail strip, as the air not only drives the ram or hammerrod, but also advances the nail strip so that there is always a nailunder the ram or hammer rod. This ram or hammer rod is formed with ahardened concave driving nose so that a shearing force will be appliedto the plastic carrier strip when the hammer descends.

The entire frame may be constructed oi aluminum or magnesium, or otherlight materials, and the various passages are constructed by the usualcoring methods used in casting operations.

Various changes in the details of construction, their arrangement andcombination, may be resorted to, within the scope of the claims formingpart of the patent which may be granted on this application.

Having described my invention, I claim as new:

1. In a nailing machine, a pneumatically advanced reciprocable hammer,yielding means to retract said hammer, means to guide a carrier stripalong a path which lies perpendicular to the hammer, said carrier stripbeing adapted to support a plurality of nails in spaced relation withtheir axes parallel to the axis of the hammer, means to admit air underpressure behind the hammer to advance it against the force of theyielding means and drive it against a nail carried by the carrier strip,and means to direct an air blast against the carrier strip to move it,and advance the next successive nail carried thereby into a position tobe struck by the hammer.

2. In a nailing machine, a pneumatically advanced reciprocable hammer,yielding means to retract said hammer, means to guide a carrier stripalong a path which lies perpendicular to the hammer, said carrier stripbeing adapted to support a plurality of nails in spaced relation withtheir axes parallel to the axis of the hammer, means to admit air underpressure behind the hammer to advance it against the force of theyielding means, and drivedt against a nail carried by the carrier strip,and means to direct air exhaust upon the return stroke of the hammeragainst the carrier strip to advance it and move the next successivenail into a position to be struck by the hammer.

3. In a nailing machine, a cylinder, 9. piston operable in the cylinder,a hammer carried by the piston, yielding means to normally hold thepiston and hammer in retracted position, means to guide a carrier stripacross the path of the hammer, said carrier strip being adapted tosupport a plurality of nails in spaced relation for successivepresentation to the hammer in a position to be driven into work by thehammer, means to admit fluid under pressure into the cylinder to drivethe piston and hammer against the pressure of the yielding means, andmeans to direct an air blast against the carrier strip to move it andadvance the next successive nail into the path of the hammer.

4; In a nailing machine. a pneumatically advanced reciprocable hammer,yielding means to retract said hammer, means to' guide a carrier stripalong a path which lies perpendicular to the hammer, said carrier stripbeing adapted to support a plurality of nails in a position parallelwith the direction of movement of the hammer,

retract said hammer means to guide a carrier strip along a path whichlies perpendicular to the path of the hammer, said carrier strip beingadapted to support a plurality ofnails in spaced relation with theiraxes parallel to the axis of the hammer, means to admit air underpressure behind the hammer to advance it against the yielding means anddrive a nail held by the carrier strip, and means to direct an air blastagainst the carrier strip upon retraction of the hammer to advance thestrip and move the next successive nail into the path of the hammer.

6. In a nailing machine, a pneumatically advanced reciprocable hammer,yielding means to retract said hammer, means to guide a carrier stripalong a path which lies perpendicular to the path of the hammer, saidcarrier strip being adapted to support a plurality of nails in spacedrelation with their axes parallel to the axis of the hammer, means toadmit air under pressure 15. Number behind the hammer to advance itagainst the yielding means and drive a nafl held by the carrier strip,and means upon the return stroke of the hammer to direct exhausted airagainst the carrier strip to advance it and move the next succesive nailinto a position to be struck by the hammer.

WILLARD E. KENDALL.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Name Date 565,074 Goddu Aug. 4, 1896 1,703,458Rufl Feb. 26, 1929 1,753,499 Burger Apr. 8, 1930 1,841,217 Seizer Jan.12, 1932 20 1,980,967 Moody Nov. 13, 1934 FOREIGN PATENTS 7 NumberCountry Date I 568,718 France Mar. 31, 1924

